Optical Word List

Astigmatism - is a visual defect whereby the surface of the lens or cornea is irregular, this causes the image to form at two planes

Short Sightedness (Myopia) - Is a visual defect whereby the objects that are far away appear blurred.

Long Sigtedness (Hypermetropia) - Is a visual defect whereby a person has difficulty in near point task, and may develop problem for distance vision at a later stage.

Presbyopia - Is the hypermetropia which develops at or around the age of forty.

Prescription - ('Rx' for short) is a specification of the lenses needed by the patient.

Optics - Is a term derived from a Greek root and means 'pertaining to the eyes or sight'.

Optometrist - Is a qualified person who diagnoses. treates and assesses the conditions of the eye and prescribes as well as dispenses spectacles and contact lenses.

Dispensing Optician - Is a qualified person who dispenses prescribed spectacles and contact lenses and other optical appliances when needed.

Photochromic lenses - These are lenses which darken when exposed to dayligh and fade in low illumination.

Bifocals - These are lenses having a distance viewing portion and a segment for reading vision.

Transitions - These are lenses which are photochromic but are made of plastic.

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